Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses:
Research and development (including related party expenses of $0 and $143 for the three months ended September 30, 2021 and 2020, respectively, and $2,359 and $458 for the nine months ended September 30, 2021 and 2020, respectively)	$ 20,428	$ 16,410	$ 55,337	$ 58,903
General and administrative	6,523	4,898	18,487	11,225
Total operating expenses	26,951	21,308	73,824	70,128
Loss from operations	(26,951)	(21,308)	(73,824)	(70,128)
Other income (expense), net:
Interest expense			(7)	(7)
Interest income	90	33	245	212
Grant income	299	787	677	2,152
Realized gain on marketable securities	1		2
Foreign currency transaction gains (losses)	(54)	(530)	1,393	(709)
Total other income (expense), net	336	290	2,310	1,648
Net loss	$ (26,615)	$ (21,018)	$ (71,514)	$ (68,480)
Net loss per share, basic and diluted	$ (0.51)	$ (0.41)	$ (1.39)	$ (3.06)
Weighted-average shares outstanding, basic and diluted	52,187,303	50,895,358	51,627,249	22,354,212